Steam generator



Inventor M Allorneys G. A. BRYAN STEAM GENERATOR Filed March 9. 1922 July 5, 1927.

July 5,1927. 1,634,351

G. A. BRYAN STEAM GENERATOR Filed March 9. 1922 2 Shgts-Shaet 2 m., Vwl AMW Patented July 5, 1927.

UNITED STATES PATENT OFFICE..

GEORGE ALFRED BRYANQOF PERU, INDILLNA,v SSIGNOR T0 BRYAN HARVESTER COMPANY, INC., A CORPOBATICN OF NEVI MEXICO.

STEAM GENERATOR.

Application led March 9,

My invention relates to steam generators or boilers and, more particularly, to portable steam generators such as are used on steam tractors, trucks and other self-propelled vehicles, in which a liquid fuel is employed. In some aspects of my invention, it is chieiiy applicable to steam generators of the type shown in my copending application, Serial No. 490,354, filed August 6, 1921. .That type of steam generator consists essentially of two bottom or base headers provided attheir ends with upstanding Water legs which communicate at the top with intermediate steam separating drums, and a dry steam drum communicating with both of the intermediate separating drums. lfiater tubes join each header with the respective intermediate drum, and these tubes are bent to run back and forth across the generator, the tubes of the two sets alternating with each other and being nested very closely together. A suitable source of heat, such asa liquid fuel burner, is provided underneath the Water tubes. The water level is normally within the separating drums.

It is common with steam generators of this type to dispose the superheating and fuel vaporizing coils in the fire pan directly over the burners. Due tothe extreme heat to which they are subjected in'that location, it is necessary to make them of some special metal, such as nichrome, and practice has demonstrated that even though such expensive metals are employed, these coils burn out with comparative frequency. In order to renew them when such an accident occurs, itis necessary to take olf the fire pan -with its inclosed burner construction to afford access to the coils.

A general object of my invention is to obviate the ydisadvantages above referred to. Various other objects and advantages of my invention` will appear from the description hereinafter of the construction chosen for the purpose of illustration.

To render the `superheating and fuel vaporizing coils more easily accessible and also to permit of the employment .of a cheaper metal in their composition, I propose to take these coils out of the iire'pan and support them on the water tubes, preferably the lowermost bend thereof, immediately above the burners. If necessary an additional turn foreach coil may be employed in order to obtain the samecapacity. In order to make 1922. Sera1-No. 512,204.

these heating coils readilyy accessible and in order that they may not interfere with the removal of the water tubes, the bends of the water tubes upon which the coils are supported, are shortened, so as not to overlap. My invention also includes various other features of construction, and details and arrangement of parts, as will hereinafter more fully appear. I shall now describe the illuS.- tratedembodiment of my invention and shall thereafter point out my invention in claims. -ligjure i is more or less conventional representation in planof a steam tractor embodying my invention, Y

Figure. 2 is a rear end elevation of the boiler or steam vgenerator and associated parts with `the frame and jacket in section;

.Figure 3 is a horizontal section of the generator on line of lfigure 2;

I-Figure 4; isa detaihpartially in section, of my improved fuel vaporizing coil.

' Referring to Figure l, it will be seen that the boiler, icated generally by the reference charact situated at the front end o t the tractor frame, and that the trans? njiission gear f2 is situated on the rear axle along'with 4the differential, while betweenr the boiler and the transmission case the steam engine, indicated generally by thedeferencecharacter 3, rlShe boiler, which is enclosed within the jacket 4, has two U shaped side nir-,nibers 5 and 6, constituting` a buse header 'and two upstanding Water s, two intermediate separating drums nfl 8 with which `the top ends of the two 7 a sie: members, respectively, communicate, anc a dry steam drum 9 communicating with the two intermediate drums 7 and 8. Two sets of water tubes, 10 and` 11, connect the base headers of t-he side members 5 and 6 with the intermediate drums 7 and 8, respectively. These vwater tubes are bent upon then "es run back and forth across the ercept the lower bends thereof which extend onlyv half way across, so as not to overlajnas indicated in Figure 2.

lilithin Athe intern'iediate drums 7 and 8 neark the top thereof. are supported f extending baille plates 12 and 13. respectively, and the upper ends of the water tubes i0 and l1 are extended up into the intermediate drums close to the under side of the balie plates 12A and 13, as shown. 'F he ce ununirat-ing pipes between the dry steam drum 9 and the intermediate drums 7 and 8 enter the top of the intermediate drums, so that the baffle plates are disposed between the outlet ends of the two water' tubes 10 and 11 and the openings tothe pipes leading to the'steam drum 9. In this way, the mingled water and steam from the pipes 10 and 11 are caused to strike'the baille plates and the water returns by gravity while the steam rises from the more'or less quiescent water in the drums 7 and 8, and passes over into the drum 9 with a minimum of prin'iing. The water in the entire system is thereby kept steadier and consequently the readingin the water level indicator is more constant. f

Underneath the boiler is a lire pan 14 inv which are the burners'15 of usual construction for vaporized liquid fuel. Supported upon the bottom short bend of the water tubes 11, is the vaporizer coil 16, while the super-heating coils 17 for the same are disposed upon the bottom short bend of the water tubes 10. Steam is taken off from the steam drum 9 at an outlet 9ZL in its rear end through pipe 18, whence it passes to the throttle 19 and from thence to a suitable governor 20, and from thence through pipe 21 to the superheater 17. From the superheater it passes through pipe 22 to the valve chamber of the engine 3. The superheater coil is shown as made in a series of as many hair-pin bends as are necessary, the bends being substantially the full length of the boiler. In this way the superheater is supported throughout its length down close to the fire and yet is not within the flame. It is, therefore, less liable to burn through.

The vaporizer coil 16 is of a similar shape to the superheater coils, one end being connected to the inlet pipe 23 for the fuel, which leads from a suitable pump (not shown) in the usual way, and the other end. is connected by a pipe 24 to an automatic cut-oil' 25. A pipe 2G which connects with the outlet end of the automatic cut-off 25, terminates in a iet directed into the usual air mixing chamber from whence it is led through branch pipes, as shown, underneath the burner 15.

In addition to the fact that the vaporizer and superheating coils are supported outsidelof the flames, although in the region of relatively great heat` an advantage of this supporting` construction is the ready accessibility of these coils. If one of the coils burns out, it is only necessary to open the door of the jacket 4 on that side, uncouple the connections at the ends of the coil, remove the coil and replace it with a new one. Also, if occasion arises to remove one of the water tubes, it is only necessary to remove the heating coil supported by the tubes on that side before uncoupling the water tube and removing it. Due to the fact that the bends on which the heating coils are supported do not overlap, the heating coil supported on the other side of the boiler does not interfere with the removal of the water tube.

The vaporizer coil lwis shown vvin detail In Figure 4. In each-straight length anA individual cable 27 of twisted wire is provided. To permit the ready insertion and removal of these cables, an opening 28 is provided at each bend, so arranged that cable 27 of either leg may be withdrawnor inserted through this opening. These open'- ings 28 are closed with suitable screw plugs 29.

It is obvious that various modifications maybe made in the construction shown in the drawings and above particularly described within the principle and scope of my invention.

I claim:

`1. In a steam generator, a water circulating system includingV two base hea-ders and for each base header a superposed steam separating drum, and two setsof watertubes joining the respective headers ywith the su# perposed steam separating drums, the water tubes being bent upon themselvesv to run back and forth across the generator and the bends of the two sets in one plane being shortened so as not to overlap.v i

j 2. In a steam generator, ak water circulating system including two base headersand for each base header a superposed steam separating drum, two sets of water tubes joining the respective headers with the'superposed steam separating drums, the'` water tubes being bent upon themselves to run back and forth across the generator andthe bends of the two sets inone plane beingshortened so 4as not to overlap, a heating coil support'- ed in the said shortened bends of one ofthe sets of water tubes, and a .source of heat underneath the generator. i

3. In a steam generator. a water circulating system including two base headers, two superposed steam separating drums, two sets of water tubes joining eachheader with its respective drum, the water tubes being bent upon themselves to run back and forth across the generator and having their lowermost bends shortened so as not lto overlap, a steam superheating coil disposed in the said shortened bends of one set of water tubes, vand a source of heat underneath the generator.

4. In a steam generator, a water circulating system including two base headers, two superposed steam separating. drums, two sets of water tubes joining each header with its respective drum, the water tubes being bent upon themselves to run back and forth across the generator and having their lowermost bends shortened sol as not 'to overlap, a steam superheating coil disposedin the said shortened bends of one set of water tubes, a, fuel vaporizing coil disposed inthe said shortened bends of the other set of water tubes, and a source of heat underneath the generator.

5. In a steam generator, a Water circulating system including two base headers and two sets of water tubes communicating at their lower ends with the respective headers and bent upon themselves to run back and forth across the generator, the bends of the two sets in one plane being shortened so as not to overlap, a steam drum in communication With the upper ends of the Water tubes, a steam superheating coil communicating with the steam drum and disposed in the said shortened bends of one .set of Water tubes, and a source of heat underneath the generator.

6. In a steam generator, a Water circulating system including tWo base headers and two sets of Water tubes con'nnunicating at 20 the lower ends to the respective hea-ders and bent upon themselves to run back and forth across the generator, the bends of the two sets in one plane being shortened so as not to overlap, a steam drum in communication with the upper ends of the Water tubes, a steam superheating coil communicating with the steam drum and disposed in the .said shortened bends of one set of Water tubes, a liquid fuel burner underneath the generator, and a fuel vaporizing coil communicating with the burner and disposed in the said shortened bends of the other set of Water tubes.

In Witness whereof, hereunto subscribe 35 my signature.

GEORGE ALFRED BRYAN. 

